Arrangement for emptying pit casks



Dec. 7, 1965 A. B. NOREN 3,221,914

ARRANGEMENT FOR EMPTYING PIT CASKS Filed Nov. 19, 1963 INVENTOR.

g'rroRNP s United States Patent ARRANGEMENT FOR EMPTYING PIT CASKS Anders Bertil Noren, Djursholm, Sweden, assignor to Bolidens Gruvaktiebolag, Stockholm, Sweden, a jointstock company limited of Sweden Filed Nov. 19, 1963, Ser. No. 324,716 Claims priority, application Sweden, Nov. 23, 1962, 12,626/ 62 Claims. (Cl. 214-623) The present invention relates to a process for emptying pit casks which have been elevated by means of a hoist or the like into emptying position from an underlying pit.

Hitherto, pit casks have been used in mining operations in many cases to haul broken deposits from the pit, workman being stationed at the opening of the mine shaft to carry out the task of emptying the elevated casks into suitable chutes or the like situated at the side of the shaft. The cask is then emptied by means of the hoist which is lowered so that the cask is suspended upside down and emptied into a chute. In this lowering process, great wear occurs on the brakes of the hoist.

The above problem, however, is eliminated by the invention which is principally characterized in that the pit cask is stopped in a predetermined emptying position and thereafter caused to tilt by a discharge chute which is inserted in the emptying zone to receive the discharged material.

The invention also relates to an arrangement for carrying out the process according to the invention, which arrangement is principally characterized by a pit cask pivotally suspended in the hoist and a discharge chute cooperating with the pit cask and movable between a retracted position and a receiving position, which chute is arranged during its movement to actuate the pit cask into emptying its contents.

The invention will be further explained below with reference to an embodiment diagrammatically illustrated in perspective in the enclosed drawing, and in connection with this, further characteristics of the invention will be set forth.

In the drawing, which principally shows a vertical section through a part of a pit shaft 1, a hopper is designated by reference numeral 2, through which a pit cask 3 is elevated to a predetermined upper stop position in which the cask 3, shown with solid lines, is presumed to be in the drawing. The cask 3 has substantially the shape of a bucket with a pivotally arranged carrier yoke 4. The cask is suspended in an elevator line 5 by the yoke 4, which line 5 is driven by a hoist, not shown, in the normal manner. In addition, two vertical guide lines 6 and 7 run parallel to line 5, on which two lines 6 and 7 a guide yoke 8 is threaded running freely on them. This yoke 8 is attached at a fixed distance from the pit cask at a point 9 and is arranged to cooperate with a limit switch 10 which, on contact with the yoke 8, ensures that the drive motor for the hoist is stopped when the pit cask has come up into a predetermined stop and introductory emptying position, i.e., the position represented by the cask 3 shown in the drawing with solid lines.

In addition, two parallel arc-shaped guide rails 11 and 12 are shown in the drawings situated at a distance from each other, on which runs a discharge chute 14 resting on runners 13, the chute consisting of a bottom with two vertically projecting screens or walls and a rear screen 15 presenting a backward projecting connection plate 16 provided with a slot 17 open towards the cask, the slot, in the opposite direction, presenting a constricted part 18 for a purpose which will later become evident.

The discharge chute 14 is connected by two pull lines to a special hoist or the like 20 intended for driving the emptying chute from the lower end position, drawn with 3,221,914 Patented Dec. 7, 1965 ice solid lines, to the upper receiving position 21, shown by broken lines. The discharge chute 14 is arranged in its upper receiving end position to actuate a limit switch 22 which in turn operates the drive machinery 20 so that this machinery is caused to stop in the receiving end position.

Furthermore, it can be mentioned that the pit cask 3 carries a ball 23 suspended from the center of the bottom plate, which ball suitably hangs from a chain or the like.

When the cask 3 consequently passes up through the hopper 2 and the yoke 8 strikes the limit switch 10, the drive machinery of the hoist is stop ed automatically at the same time that an impulse is given to the motor of the drive machinery 20 to begin work. The feed chute 14 is raised therewith, guided by the curved guide bars 11 and 12, to the upper position 21 shown with broken lines, the chute striking against the limit switch 22 which then gives an impulse to the drive motor to stop. During upward movement of the chute along the rails, however, the slit 17, cut in the plate 16, will automatically capture and guide the chain of the suspended ball 23 in the narrower section 18 of the slit in the plate, the bottom of the pit cask being carried upwards, while tilting around the yoke leads to the emptying position 24 shown with dotted lines, the material in the cask being completely emptied during some seconds and passing down into the discharge chute 14 to a storage position or the like. After a certain predetermined time interval has passed the drive machinery 20 is set in motion in the opposite direction, the chute 14 moving downwards to the normal position shown with solid lines. When the chute has come down to this position it actuates a further limit switch 25 so that the drive machinery 20 stops and blocking of the hoist ceases so that the hoist resumes operation and again lowers the cask into the pit shaft to be refilled.

On return of the discharge chute 14 to the lower position, the ball and chain are freed automatically from the slit 16 of the plate so that the pit cask is again free.

By means of the arrangement shown and described, emptying of pit casks can be carried out completely automatically without relying on man power for any purpose other than control, which thus renders .the arrangement more economical and contributes towards preventing accident risks.

The invention is not limited to the embodiment shown and described but can be varied in many ways within the spirit and scope of the invention.

Having now described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. An apparatus for emptying pit casks which have been elevated to an emptying station from an underlying pit comprising, in combination, means to elevate a pit cask comprising hoisting means, a carrier yoke attached to one end of a line of said hoisting means, and means to drive said hoisting means; a pit ca'sk pivotally mounted in said carrier yoke, a discharge chute, means at said emptying station to guide said discharge chute, means to drive said chute between a retracted position and a receiving end position, means on said chute to cause said cask to empty as said chute moves to the receiving end position, a first limit switch located at said emptying station, said first limit switch being actuated by said carrier yoke to stop said hoisting means drive means and actuate said chute driving means to move said chute to the receiving end position, a second limit switch located at the end of said receiving end position, said second switch being actuated by said chute to stop said chute drive means, means for actuating said chute drive means after a delay to return said chute to the retracted position, a third limit switch located at the end of said retracted position, said chute actuating said third switch to stop said chute drive means.

2. An apparatus for emptying pit casks according to claim 1 wherein said means for actuating said chute drive means after a delay comprises a timing means actuated by the opening of said second limit switch.

3. An apparatus for emptying pit casks according to claim 1 wherein said hoist is provided with guide line means thereby insuring said carrier yoke will contact and actuate said first limit switch.

'4. An apparatus-for emptying pit casks according to claim 1 wherein the means for emptying said cask comprises means depending from said cask, receiving means on said chute for cooperatively engaging said depending means thereby transmitting the motion of the chute to said cask.

5. An apparatus for emptying pit casks according to claim 4 wherein said depending means comprises a chain,

4 one end of which is attached to said cask and the other end of which is attached to a ball and the means on said chute comprises a control slot opening towards said ball, said slot being constricted at its inner end to receive the chain in gripping engagement.

References Cited by the Examiner UNITED STATES PATENTS 156,194 10/1874 Westbrooks 124-622 677,560 7/1901 Collier 214-712 713,220 11/ 1902 Howbert 214-622 980,734 1/1911 Ankrom 214-623 3,123,240 3/1964 MacAlpine 2147U9 GERALD M. FORLENZA, Primary Examiner. 

1. AN APPARATUS FOR EMPTYING PIT CASKS WHICH HAVE BEEN ELEVATED TO AN EMPTYING STATION FROM AN UNDERLYING PIT COMPRISING, IN COMBINATION, MEANS TO ELEVATE A PIT CASK COMPRISING HOISTING MEANS, A CARRIER YOKE ATTACHED TO ONE END OF A LINE OF SAID HOISTING MEANS, AND MEANS TO DRIVE SAID HOISTING MEANS; A PIT CASK PIVOTALLY MOUNTED IN SAID CARRIER YOKE, A DISCHARGE CHUTE, MEANS AT SAID EMPTYING STATION TO GUIDE SAID DISCHARGE CHUTE, MEANS TO DRIVE SAID CHUTE BETWEEN A RETRACTED POSITION AND A RECEIVING END POSITION, MEANS ON SAID CHUTE TO CAUSE SAID CASK TO EMPTY AS SAID CHUTE MOVES TO THE RECEIVING END POSITION, A FIRST LIMIT SWITCH LOCATED AT SAID EMPTYING STATION, SAID FIRST LIMIT SWITCH BEING ACTUATED BY SAID CARRIER YOKE TO STOP SAID HOISTING MEANS DRIVE MEANS AND ACTUATE SAID CHUTE DRIVING MEANS TO MOVE SAID CHUTE TO THE RECEIVING END POSITION, A SECOND LIMIT SWITCH LOCATED AT THE END OF SAID RECEIVING END POSITION, SAID SECOND SWITCH BEING ACTUATED BY SAID CHUTE TO STOP SAID CHUTE DRIVE MEANS, MEANS FOR ACTUATING SAID CHUTE DRIVE MEANS AFTER A DELAY TO RETURN SAID CHUTE TO THE RETRACTED POSITION, A THIRD LIMIT SWITCH LOCATED AT THE END OF SAID RETRACTED POSITION, SAID CHUTE ACTUATING SAID THIRD SWITCH TO STOP SAID CHUTE DRIVE MEANS. 